Integrated circuits with logic gates may be susceptible to latchup that is induced by generation of electron-hole pairs from high energy ionized particles, for example as encountered in space-based applications. The source, drain, and well regions of the logic gates can constitute parasitic bipolar junction transistors which combine to constitute a silicon controlled rectifier (SCR) in the substrate of the integrated circuit. Current from the electron-hole pairs flows through a lateral resistance between the parasitic bipolar junction transistors and turns on the SCR, inducing latchup. Wire bonded integrated circuits commonly have electrically conductive material, such as conductive adhesive or solder, on the back surface of the substrate to reduce the lateral resistance, which improves resistance to latchup. Bump bonded integrated circuits, also known as flip chips, are typically more prone to latchup, because the substrate material has a higher effective sheet resistance due to absence of conductive adhesive or solder. Reducing the resistance of the substrate of the integrated circuits during manufacture in a fab is not compatible with typical digital integrated circuit manufacturing and assembly processes, and undesirably increases costs.